Bag waxing machine



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2 Sheets-Sheet l E. iF. ANDERSON BAG WAXING MACHINE Filed April 22, 1943 BAG WAXING MACHINE Enea April 22, 'i2/,.15 2 sheefS-sheet 2 Patented ug. 6, 1946 BAG WAYING MACHINE Edwin F. Anderson, Buffalo, N. Y., assigner to Pillsbury Flour Mills Company, Minneapolis, Minn., a corporation of Delaware Application April 22, 1943, Serial No. 484,091

9 Claims.

This invention relates to an apparatus for coating and sealing the lling ends of paper bags and other containers after the same have been lled and the filling ends stitched or otherwise secured.

At the present time multiple-wall paper bags are extensively used for packaging granular and pulverized materials and such bags as made by the manufacturer are collapsed atwise and have the lower end thereof stitched, bonded or otherwise secured together to form a reinforced tab and such tab is further reinforced, coated and sealed by the manufacturer, usually with a heavy coating of wax. Such bags are tubular and are kdistended and filled with material from conventional dispensing and measuring machines whereafter th'e opposite sides of the filling end or upper end of the bag are collapsed together and secured to form an upper tab by stitching, bonding or other securing means. It is then necessary and required by Government regulations to seal and coat the upper tab so formed with a heavy coating of self-hardening material, such as wax or paraffin.

An object is the provision of simple, highly efficient apparatus which can be produced at relatively low cost and which is fully automatic and continuous in operation for successively coating a multiplicity of bags or other containers of the type described. l

More specifically it is an object to provide bag coating or waxing apparatus of the type described which employs minimum number of working parts and which utilizes a paii` of cooperating screw type conveyor elements in a dual capacity for both supporting a filled bag in inverted position for dipping the flattened filling extremity thereof in a trough containing melted wax or other coating ingredients and for also bodily moving the said bags longitudinally of the machine across th'e coating-containing trough and therebeyond to coat the tabs formed at the filling ends and to facilitate hardening of the coated tabs before the bags are discharged from the apparatus. Y

These and other objects and advantages of the invention will more fully appear from the following description made in yconnection 'with the accompanying drawings, wherein like reference .characters refer to the same parts'throughout 'the views and in which- Fig. 1 is a plan view of an embodiment of my `apparatus showing a filled bag about to be tilted into inverted position and so received by the supporting and conveying medium of my apparatus and showing several other bags Fig. 2 is a side elevation of my said apparatus;

Fig. 3 is a vertical section taken approximately on the line 3 3 of Fig. 2;

Fig. 4 is a vertical section taken on the line 4 4 of Fig. 2; and

Fig. 5 is a perspective view with some portions broken away and others shown in section of a multiple-wall paper bag lled with granular material and having its filling end coated and sealed by my improved apparatus. i

The form of my apparatus illustrated includes an elongated upright frame, as shown, comprising two series of opposed spaced posts 6 which may conveniently be constructed from metal pipe having attachment pedestals 6a secured to the lower ends thereof for bolt or screw attachment to a horizontal supporting surface or floor. Opposed pairs of said posts 6 may be secured together and braced by transverse pipes or other suitable members l.

At the upper portion of the elongated frame so constructed a pair of parallel spaced rotary shafts 3 are suitably journalled and extend throughout the length of the frame and have the right hand ends thereof journalled in suitable bearings 9 attached to the two respective right hand end posts 6 of the frame. The left hand Aends of the rotary shaft 8 are journalled in similar bearings it mounted at the upper ends of the respective left end posts of the frame. The axes of the two parallel shafts 8 are aligned in a plane inclined slightly from the horizontal from the right hand ends of their left hand extremities. Additional bearings l l for the medial portions of the elongated rotary shafts 8 are provided at the upper end of the intermediate posts 6. Shafts 8 are connected for driving in opposite directions and constitute a supporting medium for the bags which are to be processed, as well as a conveying medium for moving the filled bags through' the machine horizontally and longitudinally of the 'progressing the bags. The double screw conveyor may be conveniently formed by securing, by welding or other suitable means, a helical coil 8a of rod material to the external periphery of the shafts 8. The` helical coils 8a are broken or interrupted at the medial portions of the respective shafts 8 to accommodate the central bearings Suitable driving means are provided for the two rotary shafts and as shown comprise for each shaft a beveled gear I 2 mounted on the inner end of a stub shaft I2al which is journalled in a suitable bearing i3 mounted on one of the left end posts adjacent the lower portion thereof and having its axis disposed in a plane parallel with the axis of the shaft bearings I0.

Bevel gears I2 are meshed with smaller beveled gears i4 fixed to a transverse shaft I5 journalled at its respective ends in suitable self-aligning bearings I5a and as shown supported on a pair of pedestals I6. Shaft I5, as shown, as provided with a large central sprocket I1 which is driven by a roller chain I8 fromV a relatively small sprocket le which is shown as affixed tc the armature shaft of a motor M. The gear ratios between the driving sprockets and beveled gears are of such relation to the windings of the screw conveyors formed on shafts 8 that bags or other articles delivered to the receiving end of the shafts 8 will be progressed steadily and comparatively rapidly. Each of the shafts 8 is directly driven from its left hand end by a chain 2li which is trained about a sprocket 2I on the outer end of the related stub shaft l2a and about a sprocket 22 fixed to the outer end of the appropriate shaft 8.

A pair of spaced horizontal guide rails 2li hav- `ing smooth, rectilinear, opposed faces are suitably supported by angle irons Gb which extend inwardly and then upwardly from the upper ends of the two series of posts 6 and are spaced apart the' appropriate distance and mounted at the proper height for effectively guiding the filled bags B in their travel through my apparatus. These guides 2li as shown extend throughout the greater part of the length of the machine. The guide 2t on the forward side of the machine (Figs. 1 and 2) extends parallel with the conveyor shafts 8c. from the receiving end of the machine to a point within a fewV feet from the driving transmission M and then has a section 24a angled obliquely with reference to the main section 24 for directing thev bags laterally outwardly of the machine. The opposite or rear side guide 24 terminates a foot or so short of the connection of the angled deflecting guide section 24a leaving a lateral opening in the rear guarding wall to permit discharging of the bags automatically and laterally of the machine, thelateral discharge causing the bags to fall or tilt to substantially horizontal position in leaving the supporting conveying shafts.

Directly below the right hand portion of the double screw conveyor formed by shafts 8 with the helical windings 8a'. therein, is mounted an elongated narrow horizontal coating trough 21 containing coating material such as melted wax and as shown supplied with the wax or other coating material from a heated supply tank 28 'mounted at the right hand end ofthe machine and having a supply connection or conduit 29 provided with ashutoff valve 29a adjacent the tank. In the bottom of the'tank, as shown, I provide a U-shaped coil or steam pipe 39, the ends of which extend through the right hand end of the wax trough and are sealed therewith and connected to a suitable source and return pipe of a steam line. Trough 21, as shown, extends from a, point adjacent the right hand end of the machine throughout slightly greater than half the length of the shafts 8, the forward end of the trough, as shown, being inclined.

As illustrated, my apparatus provides a. means "for intermittently delivering filled bagsto the right hand end of the machine and for tilting such bags during the delivery to inverted position to properly dispose the same upon the supporting and conveying shafts 8 with the secured filling end. thereof positioned between the shafts 8 and depending therebelow into the upper level of the melted wax or coating liquid within the tank 21. The delivery mechanism illustrated comprises an inclined elevator or booster 32 of endless conveyor type driven at its upper or delivery end by suitable means such as a chain driving connection 33 which may be trained about a suitable sprocket driven by chain or other connection 34 from a sprocket 35 fixed to the right hand end of one of the rotary shafts 3. The delivered bags are guided downwardly into vertical position centrally of the two shafts 8a by opposed downwardly converging centering plates 36 and 31 respectively.

Operation The particular type of multi-wall paper bag illustrated in Fig. 5 of the drawings comprises, before being filled, a multiple tubular construction pleated and folded flatwise along longitudinal edges throughout the several pliesI of the material. The bottom edges of the bag are secured together by the manufacturer by folding a strip 1li! of heavy reinforcing flexible material and this strip is lock-stitched at 4I in folded form through the upper and free edges thereof or through the several layers of paper constituting the tubular portion of the bag. In the manufacturing of the bag, the reinforced and stitched lower edge is usually sealed and protectively coated by the manufacturer with wax or other suitable air hardening coating material.

The bag B is, of course, distended and suitably held for filling with the upper or filling end open and granular or pulverized material is` dispensed therein by a suitable dispensingmachine, not shown, the bag Ibeing filled to a point somewhat below the upper end thereof. The filled bags then have their upper ends collapsed together in `the manner of the lower ends previously described and a strip of reinforcing paper or material 40 is folded over the free edges of the filled end of the bag and stitched therethrough in the manner previously described. The bag so filled, with the upper lling end secured and reinforced, is ready for processing by my improved apparatus.

The filled bags with thellin'g en'ds's'ecured and reenforced as previously described are-'disposed upon the endless conveyor or booster 32 automatically or manually, as the case may be,

mally upper ends thereof which have justY been closed and stitched, being positioned downwardly with the wide tab disposed betweenpthe shafts 8 and depending therebelow into theV melted wax trough 21. The bags are guided by the spaced screw `conveyor shafts 8' in cooperation With the `gud'e'railings 24 and shafts l8- being rotated in opposite directions for conveying purposes. The

bags arel progressed.v or moved longitudinally through the machine witlithe depending tabs dipping into the wax in the trough'21.

it will be noted that the wax 1eve1 L of the trough V2I'is naturally disposed horizontally and at a'slight acute angle to the slightly upwardly inclined conveyor shafts 8 whereby the tabs will clear, or substantially clear, the left hand end of the trough as the bags pass over that end in movement through my machine. Thereafter further movement or travel of the bags from the forward end of the trough to the delivery end of the-screw conveyor shafts i` affords adequate time for the wax or other coating material to dry and harden before the bags are delivered. As

- the bags move to the delivery end of the machine the angled guide section 24a causes lateral delivery of the bags from the rear side of the machine and the bags in discharge will fall horir4 zontally.

Throughout this operation it will be noted that `the rotary shafts 8 with the conveyor coils 8d secured thereto serve both the function of constituting the support for the inverted upright filled bags as well as the mechanism for moving the bags longitudinally through the machine. The rounded or rod construction of the conveyor coils prevent any cutting or injury to the bags in the conveyor action. The gear ratios of the transmission mechanism, including the motor sprocket I9, large sprocket H, bevel gears M with meshed bevel gears I2 and the relation thereof to the pitch of the conveyor convolutions, are proportionedand related to cause the bags to be progressed in close spaced relation as fast as they are delivered by the elevator 32. Thus the machine has a high capacity for work and requires no manual labor in so far as the tilting of the bags, disposal of the same in upwardly inverted position on the shafts 8a, progression of the bags through the machine and coating of the depending tabs, as well as drying, are concerned.

From the foregoing description it will be seen that I have provided a simple, comparatively inexpensive and highly eicient apparatus, capable of production at low cost, and which is fully automatic and continuous in operation for successively coating the secured filling ends, of flexible containers, such as paper bags and the like.

It will further be seen that I have provided a simple, inexpensive and highly emcient method for successively coating by continuous operation a multiplicity of iiexible bag ends after the bags have been filled and the filling ends secured.

My method will be apparent from the foregoing description relating to operation and structure of my apparatus and consists generally in rst inverting a filled bag having the filling end collapsed and secured to form a tab and thereafter moving the inverted bag through a substantially horizontal. course while immersing the lower tab or secured edges of the bag in selfhardening coating, material such as wax, throughout at least a portion of the traveling movement of the bag. Additional steps of my method include preferably the further movement of the bag throughout the predetermined course after the depending secured edge or tab thereof has passed from the coating material to allow the coating material to harden. More specilically my method includes the receiving, supporting and conveying of the inverted filled and secured bags through a combination support and conveying medium which also has guiding functions in assisting and maintaining the bags as they are processed in upright position.

It will, of course, be understood that various changes may be made in the apparatus and that '6 specific details of the steps and variances in the sequences thereof may be made all Within the scope of my method invention.

What is claimed is: l

l. Apparatus for coating and sealing the secured and collapsed filling end of a filled paper bag or the like having in combinationl a combination supporting and conveyor medium disposed substantially horizontally for receiving the closed and secured lling end of a filled bag, 'said medium having a central longitudinal slot extendingthroughout the greater part of its length for accommodating the projecting secured exn tremity of said bag and having'opposed, cooperating elements adapted to only frictionally engage the opposite sides of the filled bags, and a trough mounted directly below said conveyor for containing coating material at a le'vel to cover said projecting portion of the closed end of said bag and coat the same during a part of the travel of said bag on said conveyor, Said conveyor extending for Isome distance beyond said trough to allow thecoated portion of said bags to dry and means at one end of said conveyor for facilitating removal of the processed bags therefrom.

2. Apparatus for coating and sealing the secured and collapsed filling end of a filled paper bag or the like having in combination, a pair of spaced elongated screw conveying and supporting shafts disposed in substantially a horizontal path, the convolutions ofthe screwelements of said shafts being spaced much closer than the width of said iilled bag, means for driving the same, guiding means disposed above said shaft and substantially horizontally disposed for engaging and guiding the vertical sides of bags to be processed,l said shafts being positioned for receiving an inverted filled bag having its filling end collapsed and secured to form a downwardly projecting tab, said shafts being of va diameter to at least partially support said bags with the tabs depending downwardly at one side of said shafts, and a trough mounted directly below said shafts and containing coating material at a level to cover said projecting tab and coat the same during a part of the travel of `said bags along said conveying shafts.

3. Apparatus for coating and sealing the secured and collapsed filling end of a filled paper bag or the like having in combination, a pair of spaced parallel screw conveying shafts disposed in substantially horizontal relationship for successively receiving at one end of said apparatus a series of inverted filled paper bags or the like with the filling ends thereof collapsed and secured together to form depending tabs accommodated in the space between said parallel shafts, the screw elements of said conveying shaft having their convolutions spaced much closer together than the widths 0f said filled bags rto only engage frictionally, opposite side portions of said bags, means for driving said screw conveyor shafts in opposite directions to progress said bags, and a trough mounted below said shafts and containing coating material at a level to cover said projecting tabs during a part of 5. The structure set forth in claim 3, and said shafts extending considerably beyond said trough for drying the coating material before delivery of said bags and means associated with the outer ends of said shafts for automatically discharging said coated bags laterally of said apparatus.

6. Apparatus for coating and sealing the secured, projecting and collapsed lling ends of filled paper bags or the like, having in combination a combination supporting and conveying medium, comprising a pair of parellel substantially horizontal conveyer elements adapted to engage opposite sides of the bottom portion of inverte-d bags and spaced apart to provide an elongated slot for accommodating the projecting ends ofsaid bags, means for driving said medium and a trough mounted below said parallel conveyor elements and extending longitudinally thereof and containing coating material at a level to cover said projecting ends during part of the travel of said bags upon said conveyor elemento.

'7. Apparatus for coating and sealing the se'- cured, projecting and collapsed filling ends of lled paper bags or the like, having in combination a combination supporting and conveying medium, comprising a pair of parallel substantially horizontal conveyor elements adapted to engage opposite sides of the bottom portion of inverted bags and spaced apart to provide an elongated slot for accommodating the projecting endeI of said bags, means for successively delivering a series of bags to the receiving end of said supporting and conveyor medium and for tilting 8 said bags through approximately 90 and for directing said bags to be successively supported in inverted, upright position upon said medium and means below said medium for coating the projecting secured portions of said bags during travel thereof upon said conveyor elements.

S. Apparatus for coating and sealing the secured, projecting and collapsed iilling ends of iilled paper bags or the like, having in combination a combination supporting and conveying medium, comprising a pair of parallel substantially horizontal conveyor elements adapted to engage opposite sides of the bottom portion of inverted bags and spaced apart to provide an elongated slot for accommodating the projecting ends of said bags, a cross conveyor having its delivery end disposed at some height above the receiving end of said medium and adapted to deliver filled bags substantially horizontally and to tilt said bags into inverted, upright position during such delivery, and a trough mounted below said parallel conveyor elements and containing coating material at a level to cover said projecting ends during a part of the travel of said bags upon said conveyor elements.

9. The structure set forth in claim 8, and converging, centering and guiding means between the delivery end of said cross conveyor and said medium, for assisting in precisely positioning said lled bags upon said medium in proper vertical, inverted position.

EDWIN F. ANDERSON. 

